Manufacture of bituminous compositions or pitches.



No. 791,960. Patented June 6, 1905.

NITED STATES I ATENT OFFICE.

FREDERICK J. WVARREN, OE NEWTON, MASSACHUSETTS; RALPH L. WAR- REN AND FRANK G. CUT"ER ADMINISTRATORS OF SAID FREDERICK J. IVARREN, DECEASED.

MANUFACTURE OF BITUMINOUS COMPOSITIONS OR PITCHES.

SPECIFICATION forming part of Letters Patent No. 791,960, dated June 6, 1905. Application filed April 3, 1903. Serial No. 160,919.

To (1. whom, it nutg concern: vary according to the softness of the compo- 5 Be it known that I, FREDERICK J. l/VARREN, sition or pitch. A composition or pitch which a citizen of the United States, and a resident is very soft at atmospheric temperature will of Newton, in the county of Middlesex and require a larger percentage of the powder Commonwealth of Massachusetts, haveinventthan one which is harder at such temperature.

ed anew and useful Improvement in the Man- Owing to the difference in bituminous comufacture of Bituminous Compositions or positions and pitches in this respect and owing Pitches, of which the following isa full, clear, to other differences, this range is quite large, and exact description. and while a percentage of the powder as small to I have ascertained that bituminous compoas ten per cent. may be suflicient in some cases sitions and pitches are improved for uses refor some uses a percentage over fifty per cent. quiring stability of known condition at the will be desirable for some compositions and extreme ranges of atmospheric temperatures pitches for the same or other uses. by inclusion of an impalpable powder, the Soap or other stone having the peculiar I5 powder having the effect of preventing the smooth and velvety feeling of such stone compositions or pitches from softening to an makes an impalpable powder which is peculundesirable extent at the higher temperatures iarly smooth in efiect and free from grit, and and of hardening sufliciently to become too at the same time it has a peculiar affinity for brittle at the lower temperatures. An impalcombining with the bituminous composition 20 pable powder which is very useful for this or pitch and communicating to the pitch some purpose is one obtained by reducing soapstone of its inherent qualities, so that the product or similar stone or mineral by grinding or is not only provided with the relative infiexi pulverizing to the required fineness, as an imbility to which I have referred, but is also palpable powder made from a stone having improved in quality as well. The soapstone 25 the peculiar smoothness or efiect of soapstone or other material suitable for producing a readily unites or combines with the bitumismooth gritless powder is reduced to the form nous composition or pitch and providesaprodof an impalpable powder in any desired way, not which is essentially smooth and coherent and it is combined with the bituminous comin disposition and one that serves extremely position or pitch made fluid by heat or any 30 well for the ordinary commercial uses to other desired way and intimately mingled which bituminous compositions and pitches with it by any suitable agitating means. are employed. It may be said to serve as a The product may be used in paving compofiller and a fixer as well, and that without resitions or cements and for roofing and other moving from the bituminous composition or purposes. 3 5 pitch any of its essential properties for which Having thus fully described my invention,

it is considered valuable. I claim and desire to secure by Letters Patent In practicing the invention any bituminous of the United States composition or pitch may be employed, 1. A bituminous mixture containing a biwhether derived from asphalt or coal-tar or tuminous cement or pitch having in combina- 40 from petroleum-oil, and if the bituminous tion therewith an impalpableand smooth powcomposition or pitch is of a hard character it der free from grit, derived from soapstone or 9 is softened sufliciently in any of the desired similar earthy matter. ways to make it receptive of the impalpable 2. A bituminous cement or pitch composed powder, and enough of the powder is comof relatively pure bitumen in combination 45 bined with the composition or pitch at any with a smooth, gritless, stony or earthy imtemperature to give it the desired consistency palpable powder in amount according to the for use at all ranges of atmospheric temperaintended uses. ture where the composition or cement is to be 3.. The process of rendering relatively pure employed. The quantity of the powder will bituminous cements or pitches more efficient for paving, roofing and other purposes, coni sisting in treating such bitumen With impalslstlng 1n treatlng 1t with an earthy 01' minpable soapstone in predetermined and definite era l ingredient having the characteristics of quantities.

soapstone reduced to an impalpahle, smooth F REDERIOK J. WVARREN. and gritless powder. In presence of 4. The method of decreasing the variations C. T. RoBERsoN,

in viscosity of a relatively pure bitumen con- RALPH L. VVARREN. 

